Ceramics such as silicon carbide have been used as the base material from which molding tools are manufactured for molding glass lenses. The production of molding tools from such ceramics requires the ability to polish these materials to very tight figure tolerances and a very high degree of specularity. Polishing these materials is further complicated by the desire to create non-spherical surfaces such as general aspherics (beyond conic sections), toroids and other anamorphic shapes. This is not easily done even in producing tools for molding plastic optics, let alone for producing molds to mold glass optics in high volume. Polishing a surface with a non-reciprocating mechanical device to achieve specularity and surface figure is a very difficult task. Even when such polishing is achieved, it is typically very expensive as the process is very time consuming and requires operation by highly skilled labor. The difficulty is compounded if there is a high volume application such that many of such polished tools are required for operation.
Although the polishing of mold tooling is difficult, the ability to generate challenging surfaces with precision grinding has greatly improved over the years. Interferometric testing on ground surfaces is easily performed. Surface roughness on the order of 50 .ANG. RMS is currently achievable with good figure through operation of computer numerically controlled grinders. These CNC grinders are relatively fast. Thus, it is desirable to polish ground surfaces more quickly than is possible using non-reciprocating mechanical devices of the prior art.